Fig. 6

Investigating if ethanol and the colour of syrups interfere with the alcohol saliva strip test results. Upper row: Eleven neat medicinal syrups were applied to the pad of the strips and compared to a 5% v/v PG solution in water. Photos show the zoomed images of the pads on the strips. A blue colour on the pad was observed for Beechams, Benylin Chesty, Paratusin (all ethanol-containing) whereas alcohol-free paediatric syrups (Benylin Infant and Piriteze) and alcohol-containing paediatric syrups (Calprofen) did not show any colour change. There was no blue development colour on the pads for some syrups although they were coloured due to the colour of the syrups (Covonia, OBH Combi and Dimetapp). Lower row: The syrups were pipetted into transparent plastic tubes and the colours were noted. The photos show zoomed-in images of the bottom of the tubes. Coloured syrups, such as Covonia and Dimetapp, contribute to the colour observed on the pads of the strips and therefore could interfere with the visualisation of any blue colour if EG were to be present in similarly coloured syrups.